--- /dev/null
+/*
+ * FIRMWARE Greybus driver.
+ *
+ * Copyright 2015 Google Inc.
+ * Copyright 2015 Linaro Ltd.
+ *
+ * Released under the GPLv2 only.
+ */
+
+#include <linux/firmware.h>
+
+#include "greybus.h"
+
+struct gb_firmware {
+       struct gb_connection    *connection;
+       const struct firmware   *fw;
+};
+
+static void free_firmware(struct gb_firmware *firmware)
+{
+       release_firmware(firmware->fw);
+       firmware->fw = NULL;
+}
+
+/* This returns path of the firmware blob on the disk */
+static int download_firmware(struct gb_firmware *firmware, u8 stage)
+{
+       struct gb_connection *connection = firmware->connection;
+       struct gb_interface *intf = connection->bundle->intf;
+       char firmware_name[28];
+
+       /* Already have a firmware, free it */
+       if (firmware->fw)
+               free_firmware(firmware);
+
+       /*
+        * Create firmware name
+        *
+        * XXX Name it properly..
+        */
+       sprintf(firmware_name, "ara:%04x:%04x:%04x:%04x:%04x.fw", intf->unipro_mfg_id,
+               intf->unipro_prod_id, intf->ara_vend_id, intf->ara_prod_id,
+               stage);
+
+       return request_firmware(&firmware->fw, firmware_name, &connection->dev);
+}
+
+static int gb_firmware_size_request(struct gb_operation *op)
+{
+       struct gb_connection *connection = op->connection;
+       struct gb_firmware *firmware = connection->private;
+       struct gb_firmware_size_request *size_request = op->request->payload;
+       struct gb_firmware_size_response *size_response;
+       struct device *dev = &connection->dev;
+       int ret;
+
+       if (op->request->payload_size != sizeof(*size_request)) {
+               dev_err(dev, "%s: illegal size of firmware size request (%zu != %zu)\n",
+                       __func__, op->request->payload_size,
+                       sizeof(*size_request));
+               return -EINVAL;
+       }
+
+       ret = download_firmware(firmware, size_request->stage);
+       if (ret) {
+               dev_err(dev, "%s: failed to download firmware (%d)\n", __func__,
+                       ret);
+               return ret;
+       }
+
+       if (!gb_operation_response_alloc(op, sizeof(*size_response),
+                                        GFP_KERNEL)) {
+               dev_err(dev, "%s: error allocating response\n", __func__);
+               free_firmware(firmware);
+               return -ENOMEM;
+       }
+
+       size_response = op->response->payload;
+       size_response->size = cpu_to_le32(firmware->fw->size);
+
+       return 0;
+}
+
+static int gb_firmware_get_firmware(struct gb_operation *op)
+{
+       struct gb_connection *connection = op->connection;
+       struct gb_firmware *firmware = connection->private;
+       struct gb_firmware_get_firmware_request *firmware_request = op->request->payload;
+       struct gb_firmware_get_firmware_response *firmware_response;
+       struct device *dev = &connection->dev;
+       unsigned int offset, size;
+
+       if (op->request->payload_size != sizeof(*firmware_request)) {
+               dev_err(dev, "%s: Illegal size of get firmware request (%zu %zu)\n",
+                       __func__, op->request->payload_size,
+                       sizeof(*firmware_request));
+               return -EINVAL;
+       }
+
+       if (!firmware->fw) {
+               dev_err(dev, "%s: firmware not available\n", __func__);
+               return -EINVAL;
+       }
+
+       offset = le32_to_cpu(firmware_request->offset);
+       size = le32_to_cpu(firmware_request->size);
+
+       if (!gb_operation_response_alloc(op, sizeof(*firmware_response) + size,
+                                        GFP_KERNEL)) {
+               dev_err(dev, "%s: error allocating response\n", __func__);
+               return -ENOMEM;
+       }
+
+       firmware_response = op->response->payload;
+       memcpy(firmware_response->data, firmware->fw->data + offset, size);
+
+       return 0;
+}
+
+static int gb_firmware_ready_to_boot(struct gb_operation *op)
+{
+       struct gb_connection *connection = op->connection;
+       struct gb_firmware_ready_to_boot_request *rtb_request = op->request->payload;
+       struct device *dev = &connection->dev;
+       u8 stage, status;
+
+       if (op->request->payload_size != sizeof(*rtb_request)) {
+               dev_err(dev, "%s: Illegal size of ready to boot request (%zu %zu)\n",
+                       __func__, op->request->payload_size,
+                       sizeof(*rtb_request));
+               return -EINVAL;
+       }
+
+       stage = rtb_request->stage;
+       status = rtb_request->status;
+
+       /* Return error if the blob was invalid */
+       if (status == GB_FIRMWARE_BOOT_STATUS_INVALID)
+               return -EINVAL;
+
+       /*
+        * XXX Should we return error for insecure firmware?
+        */
+
+       return 0;
+}
+
+static int gb_firmware_request_recv(u8 type, struct gb_operation *op)
+{
+       switch (type) {
+       case GB_FIRMWARE_TYPE_FIRMWARE_SIZE:
+               return gb_firmware_size_request(op);
+       case GB_FIRMWARE_TYPE_GET_FIRMWARE:
+               return gb_firmware_get_firmware(op);
+       case GB_FIRMWARE_TYPE_READY_TO_BOOT:
+               return gb_firmware_ready_to_boot(op);
+       default:
+               dev_err(&op->connection->dev,
+                       "unsupported request: %hhu\n", type);
+               return -EINVAL;
+       }
+}
+
+static int gb_firmware_connection_init(struct gb_connection *connection)
+{
+       struct gb_firmware *firmware;
+
+       firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
+       if (!firmware)
+               return -ENOMEM;
+
+       firmware->connection = connection;
+       connection->private = firmware;
+
+       return 0;
+}
+
+static void gb_firmware_connection_exit(struct gb_connection *connection)
+{
+       struct gb_firmware *firmware = connection->private;
+
+       /* Release firmware */
+       if (firmware->fw)
+               free_firmware(firmware);
+
+       connection->private = NULL;
+       kfree(firmware);
+}
+
+static struct gb_protocol firmware_protocol = {
+       .name                   = "firmware",
+       .id                     = GREYBUS_PROTOCOL_FIRMWARE,
+       .major                  = GB_FIRMWARE_VERSION_MAJOR,
+       .minor                  = GB_FIRMWARE_VERSION_MINOR,
+       .connection_init        = gb_firmware_connection_init,
+       .connection_exit        = gb_firmware_connection_exit,
+       .request_recv           = gb_firmware_request_recv,
+};
+gb_builtin_protocol_driver(firmware_protocol);
 
 };
 /* Control protocol [dis]connected response has no payload */
 
+
+/* Firmware Protocol */
+
+/* Version of the Greybus firmware protocol we support */
+#define GB_FIRMWARE_VERSION_MAJOR              0x00
+#define GB_FIRMWARE_VERSION_MINOR              0x01
+
+/* Greybus firmware request types */
+#define GB_FIRMWARE_TYPE_INVALID               0x00
+#define GB_FIRMWARE_TYPE_PROTOCOL_VERSION      0x01
+#define GB_FIRMWARE_TYPE_FIRMWARE_SIZE         0x02
+#define GB_FIRMWARE_TYPE_GET_FIRMWARE          0x03
+#define GB_FIRMWARE_TYPE_READY_TO_BOOT         0x04
+
+/* Greybus firmware boot stages */
+#define GB_FIRMWARE_BOOT_STAGE_ONE             0x01 /* Reserved for the boot ROM */
+#define GB_FIRMWARE_BOOT_STAGE_TWO             0x02 /* Firmware package to be loaded by the boot ROM */
+#define GB_FIRMWARE_BOOT_STAGE_THREE           0x03 /* Module personality package loaded by Stage 2 firmware */
+
+/* Greybus firmware ready to boot status */
+#define GB_FIRMWARE_BOOT_STATUS_INVALID                0x00 /* Firmware blob could not be validated */
+#define GB_FIRMWARE_BOOT_STATUS_INSECURE       0x01 /* Firmware blob is valid but insecure */
+#define GB_FIRMWARE_BOOT_STATUS_SECURE         0x02 /* Firmware blob is valid and secure */
+
+/* Max firmware data fetch size in bytes */
+#define GB_FIRMWARE_FETCH_MAX                  2000
+
+/* Firmware protocol firmware size request/response */
+struct gb_firmware_size_request {
+       __u8                    stage;
+};
+
+struct gb_firmware_size_response {
+       __le32                  size;
+};
+
+/* Firmware protocol get firmware request/response */
+struct gb_firmware_get_firmware_request {
+       __le32                  offset;
+       __le32                  size;
+};
+
+struct gb_firmware_get_firmware_response {
+       __u8                    data[0];
+};
+
+/* Firmware protocol Ready to boot request */
+struct gb_firmware_ready_to_boot_request {
+       __u8                    stage;
+       __u8                    status;
+};
+/* Firmware protocol Ready to boot response has no payload */
+
+
 /* I2C */
 
 /* Version of the Greybus i2c protocol we support */